   given the id and size directly, without being checked."
   ^blocks.data.Block
   [id size reader]
-  (Block. id size nil reader nil nil))
+  (->Block id size nil reader nil nil))
 
 
 (defn literal-block

  [id source]
  (let [content (collect-bytes source)]
    (when (pos? (count content))
      (Block. id (count content) content nil nil nil))))


(defn read-block

;; ## Constructors

;; Remove automatic constructor function.
(alter-meta! #'->Block assoc :private true)


(defn lazy-block
